Breast Ultrasound Following a Positive Clinical Breast Examination: Does It Have a Role in Low- and Middle-Income Countries?

Purpose: Breast cancer is the most common cancer among women worldwide, with an estimated 1.7 million new cases occurring in 2012. The majority of cases and deaths occur in low- and middle-income countries (LMICs), where population-based mammography screening is not available and countries must rely on clinical breast examination (CBE). Since ultrasound has the potential to reduce unnecessary biopsies by triaging women with palpable or focal breast findings at CBE, we searched for evidence in the literature on the effectiveness of ultrasound in detecting potential breast cancer following positive CBE findings. Methods: We reviewed the literature from 2000 to 2014 for evidence on the performance of breast ultrasound, in the absence of mammography, used to evaluate women after a positive CBE. From the studies meeting our inclusion/exclusion criteria for our analysis, we extracted data on the study design, location, ultrasound transducer parameters, patient age, method for determining positive and negative cases, and number of malignancies detected/total number of women studied. Results: We found 15 studies matching our inclusion/exclusion criteria, 9 from high-income countries and 6 from LMICs. Despite considerable variability in study design and patient populations, breast ultrasound consistently showed high sensitivity (median = 94 percent) and specificity (median = 80 percent) for detecting breast cancer and identifying normal and benign findings not requiring a biopsy. Clear patterns related to transducer frequency or income level were not discernible given the variations in patient populations and final diagnostic determinations. Conclusion: Our systematic review suggests that breast ultrasound following a positive CBE may be a powerful diagnostic test to determine those who do or do not need biopsy. We encourage further research in breast ultrasound use after a positive CBE in LMICs to assess the accuracy of ultrasound in these settings and the feasibility of widespread implementation

Pilot Study of a Resource-Appropriate Strategy for Downstaging Breast Cancer in Rural Uganda

Breast cancer incidence and mortality are rapidly increasing in low- and middle-income countries like Uganda. Shifting the proportion of women presenting with late-stage breast cancer to early-stage breast cancer (downstaging) at the time of diagnosis would substantially improve survival and efficient use of available resources. Imaging The World (ITW) conducted a pilot study in Uganda where trained village health teams (VHTs) promoted breast cancer awareness in the Kamuli District (Uganda). As a result, 212 women with self-detected lumps presented to the community health center level III (Nawanyago HCIII) for a clinical breast examination (CBE). Patients with masses on CBE were examined with breast ultrasound by a certified sonographer trained in breast imaging. Women with ultrasound-detected masses were referred to a regional health center for further evaluation. Of the 212 women, 44 (21%) had a palpable mass by CBE, 11 (28%) examined by ultrasound were recommended for biopsy, and four breast cancers were diagnosed. Providing ultrasound scanning at Nawanyago HCIII reduced the number of women travelling to the referral hospital by 75%. As a result of breast cancer awareness and ultrasound studies, we were able to diagnose breast cancer at an earlier stage than would be otherwise possible. This pilot project supports locally available breast ultrasound as a resource-appropriate strategy to downstage breast cancer in a low-income country

Spontaneous decay in the presence of dispersing and absorbing bodies: general theory and application to a spherical cavity

A formalism for studying spontaneous decay of an excited two-level atom in the presence of dispersing and absorbing dielectric bodies is developed. An integral equation, which is suitable for numerical solution, is derived for the atomic upper-state-probability amplitude. The emission pattern and the power spectrum of the emitted light are expressed in terms of the Green tensor of the dielectric-matter formation including absorption and dispersion. The theory is applied to the spontaneous decay of an excited atom at the center of a three-layered spherical cavity, with the cavity wall being modeled by a band-gap dielectric of Lorentz type. Both weak coupling and strong coupling are studied, the latter with special emphasis on the cases where the atomic transition is (i) in the normal-dispersion zone near the medium resonance and (ii) in the anomalous-dispersion zone associated with the band gap. In a single-resonance approximation, conditions of the appearance of Rabi oscillations and closed solutions to the evolution of the atomic state population are derived, which are in good agreement with the exact numerical results.Comment: 12 pages, 6 figures, typos fixed, 1 figure adde

The Samurai Project: verifying the consistency of black-hole-binary waveforms for gravitational-wave detection

We quantify the consistency of numerical-relativity black-hole-binary waveforms for use in gravitational-wave (GW) searches with current and planned ground-based detectors. We compare previously published results for the $(\ell=2,| m | =2)$ mode of the gravitational waves from an equal-mass nonspinning binary, calculated by five numerical codes. We focus on the 1000M (about six orbits, or 12 GW cycles) before the peak of the GW amplitude and the subsequent ringdown. We find that the phase and amplitude agree within each code's uncertainty estimates. The mismatch between the $(\ell=2,| m| =2)$ modes is better than $10^{-3}$ for binary masses above $60 M_{\odot}$ with respect to the Enhanced LIGO detector noise curve, and for masses above $180 M_{\odot}$ with respect to Advanced LIGO, Virgo and Advanced Virgo. Between the waveforms with the best agreement, the mismatch is below $2 \times 10^{-4}$. We find that the waveforms would be indistinguishable in all ground-based detectors (and for the masses we consider) if detected with a signal-to-noise ratio of less than $\approx14$, or less than $\approx25$ in the best cases.Comment: 17 pages, 9 figures. Version accepted by PR

Interaction between integrin α9β1 and vascular cell adhesion molecule-1 (VCAM-1) inhibits neutrophil apoptosis

According to the prevailing paradigm, neutrophils are short-lived cells that undergo spontaneous apoptosis within 24 hours of their release from the bone marrow. However, neutrophil survival can be significantly prolonged within inflamed tissue by cytokines, inflammatory mediators, and hypoxia. During screening experiments aimed at identifying the effect of the adhesive microenvironment on neutrophil survival, we found that VCAM-1 (CD106) was able to delay both spontaneous and Fas-induced apoptosis. VCAM-1-mediated survival was as efficient as that induced by the cytokine IFN-β and provided an additive, increased delay in apoptosis when given in combination with IFN-β. VCAM-1 delivered its antiapoptotic effect through binding the integrin α9β1. The α9β 1 signaling pathway shares significant features with the IFN-β survival signaling pathway, requiring PI3 kinase, NF-κB activation, as well as de novo protein synthesis, but the kinetics of NF-κB activation by VCAM-1 were slower and more sustained compared with IFN-β. This study demonstrates a novel functional role for α9β1 in neutrophil biology and suggests that adhesive signaling pathways provide an important extrinsic checkpoint for the resolution of inflammatory responses in tissues

Resonant dipole-dipole interaction in the presence of dispersing and absorbing surroundings

Within the framework of quantization of the macroscopic electromagnetic field, equations of motion and an effective Hamiltonian for treating both the resonant dipole-dipole interaction between two-level atoms and the resonant atom-field interaction are derived, which can suitably be used for studying the influence of arbitrary dispersing and absorbing material surroundings on these interactions. The theory is applied to the study of the transient behavior of two atoms that initially share a single excitation, with special emphasis on the role of the two competing processes of virtual and real photon exchange in the energy transfer between the atoms. In particular, it is shown that for weak atom-field interaction there is a time window, where the energy transfer follows a rate regime of the type obtained by ordinary second-order perturbation theory. Finally, the resonant dipole-dipole interaction is shown to give rise to a doublet spectrum of the emitted light for weak atom-field interaction and a triplet spectrum for strong atom-field interaction.Comment: 15 pages, 1 figure, RevTE

Three dimensional numerical relativity: the evolution of black holes

We report on a new 3D numerical code designed to solve the Einstein equations for general vacuum spacetimes. This code is based on the standard 3+1 approach using cartesian coordinates. We discuss the numerical techniques used in developing this code, and its performance on massively parallel and vector supercomputers. As a test case, we present evolutions for the first 3D black hole spacetimes. We identify a number of difficulties in evolving 3D black holes and suggest approaches to overcome them. We show how special treatment of the conformal factor can lead to more accurate evolution, and discuss techniques we developed to handle black hole spacetimes in the absence of symmetries. Many different slicing conditions are tested, including geodesic, maximal, and various algebraic conditions on the lapse. With current resolutions, limited by computer memory sizes, we show that with certain lapse conditions we can evolve the black hole to about $t=50M$, where $M$ is the black hole mass. Comparisons are made with results obtained by evolving spherical initial black hole data sets with a 1D spherically symmetric code. We also demonstrate that an ``apparent horizon locking shift'' can be used to prevent the development of large gradients in the metric functions that result from singularity avoiding time slicings. We compute the mass of the apparent horizon in these spacetimes, and find that in many cases it can be conserved to within about 5\% throughout the evolution with our techniques and current resolution.Comment: 35 pages, LaTeX with RevTeX 3.0 macros. 27 postscript figures taking 7 MB of space, uuencoded and gz-compressed into a 2MB uufile. Also available at http://jean-luc.ncsa.uiuc.edu/Papers/ and mpeg simulations at http://jean-luc.ncsa.uiuc.edu/Movies/ Submitted to Physical Review

Testing gravitational-wave searches with numerical relativity waveforms: Results from the first Numerical INJection Analysis (NINJA) project

The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave data analysis communities. The purpose of NINJA is to study the sensitivity of existing gravitational-wave search algorithms using numerically generated waveforms and to foster closer collaboration between the numerical relativity and data analysis communities. We describe the results of the first NINJA analysis which focused on gravitational waveforms from binary black hole coalescence. Ten numerical relativity groups contributed numerical data which were used to generate a set of gravitational-wave signals. These signals were injected into a simulated data set, designed to mimic the response of the Initial LIGO and Virgo gravitational-wave detectors. Nine groups analysed this data using search and parameter-estimation pipelines. Matched filter algorithms, un-modelled-burst searches and Bayesian parameter-estimation and model-selection algorithms were applied to the data. We report the efficiency of these search methods in detecting the numerical waveforms and measuring their parameters. We describe preliminary comparisons between the different search methods and suggest improvements for future NINJA analyses.Comment: 56 pages, 25 figures; various clarifications; accepted to CQ

Breast cancer early detection : a phased approach to implementation

Q1Q1When breast cancer is detected and treated early, the chances of survival are very high. However, women in many settings face complex barriers to early detection, including social, economic, geographic, and other interrelated factors, which can limit their access to timely, affordable, and effective breast health care services. Previously, the Breast Health Global Initiative (BHGI) developed resource-stratified guidelines for the early detection and diagnosis of breast cancer. In this consensus article from the sixth BHGI Global Summit held in October 2018, the authors describe phases of early detection program development, beginning with management strategies required for the diagnosis of clinically detectable disease based on awareness education and technical training, history and physical examination, and accurate tissue diagnosis. The core issues address include finance and governance, which pertain to successful planning, implementation, and the iterative process of program improvement and are needed for a breast cancer early detection program to succeed in any resource setting. Examples are presented of implementation, process, and clinical outcome metrics that assist in program implementation monitoring. Country case examples are presented to highlight the challenges and opportunities of implementing successful breast cancer early detection programs, and the complex interplay of barriers and facilitators to achieving early detection for breast cancer in real-world settings are considered.https://scholar.google.com/citations?user=xFiKCkMAAAAJ&hl=eshttp://scienti.colciencias.gov.co:8081/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0000264474Revista Nacional - Indexad